Valve manifold

ABSTRACT

A valve manifold having a manifold body with a first face, an opposed, substantially planar second face, and a peripheral wall, a first inlet, a second inlet, a first drain port, and a second drain port being formed in the first face, a first outlet and a second outlet being formed in the second face, there being a first, fluid communication pathway/valve for controlling fluid flow between the first outlet and the second outlet, a second, fluid communication pathway/valve for controlling fluid flow between the first inlet and the first outlet, a third, fluid communication pathway/valve for controlling fluid flow between said first drain port and said first outlet, a fourth, fluid communication pathway/valve for controlling fluid flow between the second inlet and the second outlet, a fifth, fluid communication pathway/valve for controlling fluid flow between the second drain port and the second outlet, flow paths opening into the outlets sloping away from said second face.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a valve manifold for controlling flowbetween a main flow line and a pressure sensor and, more specifically,to such a valve manifold that is self-draining.

2. Description of the Prior Art

It is often desirable to determine the flow or pressure of a fluid,e.g., a gas, through a main flow line, e.g., a pipeline. Typically, thiscan be accomplished by a flow restriction disposed in the main flowline, there being pressure taps on each side of the restriction forobtaining high and low fluid pressures. Such a flow restriction maycomprise an orifice plate, a flow nozzle, a venturi tube, etc. The highand low pressures taken from opposed sides of the flow restriction inthe main flow line are detected by a pressure sensor/transmitterassembly that measures and transmits the measured pressures or pressuredifferential by a suitable mechanical or electronic signal or the liketo a remote location, e.g., a control room, where the pressure orpressure differential may be monitored and/or recorded by an operator.

A valve manifold is normally mounted between the main flow line and thepressure sensor. The manifold is used to control flow to the pressuresensor while permitting blocking, venting, zero checks, and calibration.The manifold typically includes a plurality of valves, each movablebetween open and closed positions relative to a flow pathway in themanifold so as to control the flow of fluid through the pathway.

Fluid pressure sensor/transmitters, particularly suchsensor/transmitters of the differential pressure type typically employdiaphragms in both the low and high pressure inlets to the pressuresensor to detect the high and low pressures to which they are exposed.As disclosed in U.S. Pat. No. 5,277,224, it is desirable, in order tominimize leak paths, to minimize the interface connections between thepressure sensor and the main flow line. As also taught in U.S. Pat. No.5,277,224, this can be accomplished, in part, by directly coupling thevalve manifold to the pressure sensor. While this reduces leak paths andthe space required for the manifold/pressure sensor system, it can posesignificant problems.

Pressure sensors of the type under consideration typically employdiaphragms. These diaphragms are extremely fragile, expensive, anddifficult to install in the pressure sensor. Further, in cases where thevalve manifold and pressure sensor are directly coupled to one another,the diaphragms are closely positioned to the face of the manifold towhich the pressure sensor is attached. In these direct coupledmanifold/pressure sensor assemblies, one face of the manifold, referredto as the instrument face, sealingly abuts a face of the pressuresensor. The instrument face of the manifold is provided with a lowpressure outlet and a high pressure outlet, both of which are relativelyshallow, cylindric cavities. The cylindric cavities are in register withlow pressure and high pressure inlets, respectively, in the face of thepressure sensor sealingly abutted by the instrument face of themanifold. The diaphragms are positioned in the low pressure and highpressure inlets of the pressure sensor close to the mouths thereof.Accordingly, when the manifold and pressure sensor are mated, thecylindric cavities cooperate with the diaphragms to form generallycylindric chambers of a small cylindrical height relative to thecylindrical diameter.

Although manifold/pressure sensor assemblies of the type underconsideration can be mounted in a variety of ways, it is common, whenthe fluid pressure being measured is a gas, to mount the manifold suchthat the instrument face is generally horizontal and facing up, thepressure sensor accordingly being mounted above the manifold. It is notuncommon when measuring gas pressures for there to be condensation ofliquids in the manifold, which occurs either during or after pressuremeasurements. Any liquid remaining in the relatively shallow cylindricchambers described above, if not removed, may interfere with subsequentpressure measurements, can cause corrosion of the metal diaphragms, orin certain, adverse climatic conditions, freeze and rupture thediaphragms. Accordingly, it becomes expedient, to the extent possible,that any liquid that collects in the manifold, by whatever mechanism, beremoved. In particular, any liquid remaining in the cylindric chambersmust be removed to avoid the problems discussed above.

In cases where the manifold is utilized in pressure measurements on aliquid source, the instrument face of the manifold is generally likewisedisposed in a horizontal plane but is facing downward rather than upwardas in the case with gas measurements, the pressure sensor/transmitterbeing mounted below the manifold. In measuring liquid pressures, it isimportant, for accuracy of measurement, that the liquid in the cylindricchambers be free of gas bubbles, which could collect on the diaphragmsurface, giving a false reading. Accordingly, it is clearly desirablefor the manifold to be designed such that any gas bubbles in thecylindric chambers be provided with escape pathways that slope upwardfrom the instrument face of the manifold so that any gas bubbles in theliquid can rise out of the cylindric chambers, away from the diaphragmfaces.

It is common in prior art manifold design, in order to form therelatively complex passageway system, to utilize “construction holes,”which are simply bores in the manifold body that allow passageways to bedrilled and interconnected with other passageways. These constructionholes, even though they are plugged, are a potential source of leakage.Alternately, they frequently provide dead spaces within the manifoldbody where liquid and gas bubbles can collect. Thus, elimination of theconstruction holes eliminates one possible source of leakage and liquidcollection or pooling in the manifold body.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide animproved valve manifold.

Another object of the present invention is to provide a valve manifoldfor use with pressure sensors of the differential pressure type.

Still a further object of the present invention is to provide aself-draining valve manifold.

Another object of the present invention is to provide a wafer-type valvemanifold that eliminates the need for construction holes or other suchbores to accommodate drilling of and interconnection of internalpassageways.

The above and other objects of the present invention will be apparentfrom the drawings, the description, and the appended claims.

The valve manifold of the present invention is adapted to be positionedbetween a main flow line and a pressure sensor to control fluid flowfrom the main flow line to the pressure sensor. The manifold has a bodywith a first face, an opposed, substantially planar second face, and aperipheral wall. A high pressure inlet, a low pressure inlet, a highpressure drain port, and a low pressure drain port are formed in thefirst face, while a high pressure outlet and a low pressure outlet areformed in the second face. An equalizer valve cavity is formed in theperipheral wall and is provided with an equalizer valve that controlsfluid communication between the high pressure outlet and the lowpressure outlet. A high pressure block valve cavity is also formed inthe peripheral wall, the high pressure block valve cavity, the highpressure inlet, and the high pressure valve being interconnected, a highpressure block valve being disposed in the high pressure block valvecavity to control fluid communication between the high pressure inletand the high pressure outlet. A high pressure vent valve cavity isformed in a first, substantially planar, side surface of the peripheralwall, the first, side surface being at an acute angle relative to thesecond face of the manifold body. A straight, high pressure ventpassageway connects the high pressure vent valve cavity and the highpressure outlet, the high pressure vent passageway sloping in adirection away from the second face and being substantially normal tothe first side surface. The high pressure vent valve cavity and the highpressure drain port are connected, flow therebetween being controlled bya high pressure vent valve disposed in the high pressure vent valvecavity. In like manner to the high pressure arrangement discussed above,the manifold further includes a low pressure block valve cavity formedin the peripheral wall, the low pressure block valve cavity, the lowpressure inlet, and the low pressure outlet being interconnected, a lowpressure block valve being disposed in the low pressure block valvecavity to control fluid communication between the two pressure inlet andthe low pressure outlet. Likewise, a low pressure vent valve cavity isformed in a second, substantially planar side surface of the peripheralwall, the second side surface also being at an acute angle relative tothe second face of the manifold body. A straight, low pressure ventpassageway connects the low pressure vent valve cavity and the lowpressure outlet, the low pressure vent passageway sloping in a directionaway from the second face and being substantially normal to the secondside surface. The low pressure vent valve cavity and the low pressuredrain port are connected, flow therebetween being controlled by a lowpressure vent valve disposed in the low pressure vent valve cavity.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can best be understood with reference to the drawings inwhich:

FIG. 1 is a perspective view of the manifold of the present inventionshown as being interfaced between a pressure sensor/transmitter and asource of fluid;

FIG. 2 is an isometric view of the manifold body of the presentinvention showing one particular porting arrangement;

FIG. 3 is a top plan view of the manifold of the present invention;

FIG. 4 is an elevational view of the manifold of the present invention;and

FIG. 5 is another isometric view of the manifold body of the presentinvention, but showing the manifold inverted from the position shown inFIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The valve manifold of the present invention will be described, in part,with reference to a high pressure flow pathway system and a low pressureflow pathway system, it being understood that such nomenclature ispurely for reference purposes only. Accordingly, valves, passageways, orthe like described as being “high pressure” could be “low pressure” andvice versa.

With reference first to FIG. 1, the manifold, shown generally as 10, isseen as being directly, sealingly coupled to a differential pressuretransmitter, shown generally as 12, the transmitter 12 comprising aninput/output unit 14 and a pressure sensor or transducer housing 16containing a pair of diaphragms (not shown). One example of a suitabledifferential pressure transmitter 12 is marketed by Rosemount, Inc.,Eden Prairie, Minn., as the Model 3051C Differential PressureTransmitter. It will be understood, however, that the manifold of thepresent invention can be used with numerous other differential pressuretransmitters and, indeed, can be used to interface a source of fluid,the pressure of which is to be measured, with any type of pressuresensing apparatus whether or not such an apparatus incorporates atransmitters, employs diaphragms as the sensing element, etc. As can beseen, transmitter 12 is affixed to manifold 10, in the well knownmanner, by means of a series of bolts (not shown) that extend throughmanifold 10 and are received in threaded blind bores (not shown) orthroughbores (not shown) in transducer housing 16. Manifold 10 includesfive valve assemblies indicated generally as 20, 22, 24, 26, and 28,valve assemblies 20-28 being disposed in a peripheral wall, as describedhereafter, of manifold 10. On the face of manifold 10 opposite the faceto which transmitter 12 is connected, manifold 10 is connected to firstand second conduits 30 and 32, which, in the case where transmitter 12is of the differential pressure type, would be connected to a mainconduit or source of flowing, pressurized fluid in which an orificeplate or the like was disposed, one of the conduits being in fluidcommunication with the upstream side of the orifice plate, the other ofthe conduits being in fluid communication with the downstream side ofthe orifice plate. While in the embodiment shown in FIG. 1, manifold 10is shown as being connected to the source of flowing pressurized fluidby what are generally referred to as NPT pipe connections, it will beappreciated that other interface connecting means may be employed toconnect the manifold 10 to the source of the flowing, pressurized fluid.

As is conventional in valve manifold of the type under consideration,manifold 10 includes a fluid communication passageway leading from ahigh pressure fluid inlet to a high pressure fluid outlet, a fluidcommunication passageway leading from a low pressure fluid inlet to alow pressure fluid outlet and a fluid communication passagewayinterconnecting the high and low pressure fluid outlets such that eitherthe low or high pressure fluid can be directed to both of the high andlow pressure fluid outlets. Additionally, a typical manifold of the typeunder consideration permits venting of either the high or low pressurepassageways while the other of the high or low pressure passagewaysremains under pressure or, alternately, venting of both of the high andlow pressure passageways so that there is zero pressure at the pressuresensor. Controlling flow through the various passageways to accomplishthe above operations is accomplished by manipulation of the valves20-28.

With reference now to FIG. 2, the manifold 10 is seen to comprise amonolithic, wafer-type body 10 a of a suitable high strength material,e.g., metal. As can be seen, manifold body 10 a is in the general shapeof an elongated hexagon and includes a first face 34 that is preferablysubstantially planar and an opposed, second face 36 (see FIG. 4) thatlikewise is substantially planar and preferably parallel to first face34, second face 36 being referred to as the instrument face. Body 10 afurther includes a peripheral wall comprised of a first, substantiallyplanar, side surface 38, and a second, substantially planar side surface40, surfaces 38 and 40 being generally opposed to one another atopposite ends of manifold body 10 a, both of first and second sidesurfaces 38 and 40 being coincident with respective ones of imaginaryplanes that form acute angles with an imaginary plane coincident withinstrument face 36. The peripheral wall of manifold body 10 a furtherincludes a third substantially planar side surface 42, a fourthsubstantially planar side surface 44, and a fifth substantially planarside surface 46, planar side surface 42 being disposed between planarside surfaces 44 and 46. Sixth planar side surface 47 completes theperipheral wall of manifold body 10 a, sixth surface 47 and thirdsurface 42 being substantially parallel to one another. As can be seen,surfaces 46 and 44 form equal, obtuse angles with third surface 42. Asalso seen, sixth surface 47 is provided with threaded bores 70 and 72used with bolts to mount the manifold/transmitter assembly to a suitablebracket or other such mounting means associated with the main flowline/orifice plate assembly.

A high pressure cylindric cavity 48 and low pressure cylindric cavity 50are formed in instrument face 36 of manifold body 10 a, cylindriccavities 48 and 50, as shown, being relatively shallow, having shortcylindrical heights relative to their cylindrical diameter. Highpressure cylindric cavity 48 has a substantially planar bottom 48 awhile low pressure cylindric cavity 50 has a substantially planar bottom50 a. High pressure cylindric cavity 48 and low pressure cylindriccavity 50 provide high and low pressure fluid outlets, respectively,from manifold body 10 a such that when manifold 10 is mated to apressure sensor such as pressure transmitter 12, cylindric cavities 48and 50 are in register with respective high and low pressure inlets inthe pressure transducer housing 16 of the differential pressuretransmitter 12.

First face 34, which can be referred to as the process face of manifold10, is provided with a high pressure inlet 48 b, inlet 48 b beinggenerally cylindrical in nature and can be threaded in the well-knownmanner to receive a threaded conduit, e.g., a pipe such as NPT pipe 30.Low pressure inlet 50 b, also formed in first face 34, is generallycylindrical in nature, and, as inlet 48 b, can be threaded to receive asuitable pipe connection, e.g., NPT pipe 32. Also formed in the face 34of manifold body 10 a is a high pressure drain port 48 h and a lowpressure drain port 50 h, both of such ports 48 h and 50 h beinggenerally cylindrical in nature and being threaded if desired.

As is conventional in manifolds of the type under consideration, a fluidcommunication pathway connects high pressure inlet 48 b with highpressure outlet 48 and, likewise, a fluid communication pathway connectslow pressure inlet 50 b with low pressure outlet 50.

With reference first to the high pressure pathway, a cylindric, blockvalve cavity 48 c is formed in substantially planar, side surface 44,valve cavity 48 c being threaded in the well-known manner for receipt ofa valve such as valve 26 shown in FIG. 1. High pressure block valvecavity 48 c is connected to high pressure outlet 48 via passageway 48 d,passageway 48 d, as shown, being substantially straight, sloping in adirection away from face 36, and opening into cylindric cavity or highpressure outlet 48 at the juncture of the bottom wall 48 a and the sidewall thereof. High pressure block valve cavity 48 c is also connected tohigh pressure inlet 48 b via a straight passageway 48 e. It will beappreciated that when a valve such as block valve 26 shown in FIG. 1 isthreadedly received in valve cavity 48 c, flow between inlet 48 b andoutlet 48 can be controlled by opening and closing valve 26, valve 27operating, in the well-known manner, to open or close flow through valvecavity 48 c between passages 48 d and 48 e.

A cylindric, high pressure vent valve cavity 48 f is formed in first,substantially planar side surface 38 and is in open communication withhigh pressure outlet 48 via passageway 48 g, passageway 48 g openinginto outlet 48 at the intersection of the bottom wall 48 a and the sidewall thereof, valve cavity 48 f being threaded in the well-known mannerfor receipt of a suitable valve. As best seen with reference to FIG. 5,passageway 48 g is generally normal or perpendicular to first planarside surface 38 and is generally coaxial with vent valve cavity 48 f. Ascan also be seen from FIG. 5, passageway 48 g slopes in a direction awayfrom instrument face 36, i.e., generally downward as depicted in FIG. 4and generally upward as depicted in FIG. 5. As best seen with referenceto FIG. 3, high pressure drain port 48 h intersects vent valve cavity 48f, placing drain port 48 h and vent valve cavity 48 f in direct, fluidcommunication with one another without any cross-drilling. Disposed invent valve cavity 48 f, as shown in FIG. 1, is vent valve 28, vent valve28 serving to control flow between passageway 48 g and drain port 48 hand, more generally, to control flow between outlet 48 and drain port 48h. To this end, when valve 28 is in the closed position, open fluidcommunication between valve cavity 48 f and drain port 48 h is shut off.

With reference now to low pressure flow pathway, a low pressurecylindric, block valve cavity 50 c is formed in second, substantiallyplanar side surface 46 and is connected to low pressure outlet 50 via astraight passageway 50 d, passageway 50 d opening into cylindric cavity50 through the juncture of bottom wall 50 a and the side wall thereofand sloping in a direction away from face 36. Low pressure block valvecavity 50 c is also connected to two pressure inlet 50 b via a straightpassageway 50 e. With low pressure block valve 22 (see FIG. 1)threadedly received in low pressure valve cavity 50 c, it will be seenthat fluid communication between passages 50 e and 50 d can becontrolled via the opening and closing of valve 22. Accordingly, fluidflow between the inlet 50 b and outlet 50 can be controlled. Formed insecond, substantially planar side surface 40 is cylindric, vent valvecavity 50 f, low pressure vent valve cavity 50 f being threaded andconnected to low pressure outlet 50 via a straight passageway 50 g,passageway 50 g being substantially normal to surface 40 and openinginto cylindric cavity 50 through the intersection of the bottom wall 50a and the side wall thereof. As best seen with reference to FIGS. 4 and5, passageway 50 g slopes in a direction away from instrument face 36,i.e., in a generally downward direction as shown in FIG. 4 and in agenerally upward direction as shown in FIG. 5. Vent valve cavity 50 fintersects, and accordingly is in direct fluid communication, with drainport 50 h without any cross-drilling. With valve 24 threadedly receivedin vent valve cavity 50 f, it will be seen that fluid communication frompassageway 50 g to vent port 50 h through vent valve cavity 50 f can becontrolled.

A cylindric equalizer valve cavity 52 is formed in third, substantiallyplanar side surface 42 of manifold body 10 a. Equalizer valve cavity 52,threaded in the conventional manner, is connected by a straightpassageway 52 a to low pressure outlet 50 and to high pressure outlet 48via intersecting passageways 52 b and 52 c, passageways 52 a and 52 copening into outlets 50 and 48, respectively, at the intersections ofthe bottom surfaces 50 a and 48 a, respectively, and the side walls,respectively, of cavities 50 and 48. With equalizer valve 20 disposed inequalizer valve cavity 52 as shown in FIG. 1, it can be seen that openfluid communication between high pressure outlet 48 and low pressureoutlet 50 can be established whereby either the low or the high pressurefluid pressure can be directed to both the high and low pressure inlets,respectively, of the pressure sensors in housing 16. As best seen withreference to FIG. 3, manifold body 10 a is provided with fourthroughbores 54, 56, 58, and 60 that are used, in conjunctions withbolts not shown, to mount manifold body 10 a to transmitter 12,transducer housing 16 being provided with threaded bores (not shown) inregister with throughbores 54, 56, 58, and 60 and in which such boltsare threadedly received. It will be appreciated that instrument face 36is sealingly mated to the face of transmitter housing 16.

Thus, as described above and as used herein, “wafer-style” refers to amanifold body that is monolithic, i.e., formed from a single block ofmaterial, has opposed, spaced faces, e.g., instrument face 36 andprocess face 34, that are substantially planar and parallel to eachother, has a thickness between such opposed faces that is less thaneither the width or length of the faces, and wherein all valves aredisposed in a peripheral wall that interconnects the opposed faces—i.e.,no valves are disposed in either of the two opposed faces.

The self-draining feature of the manifold of the present invention isbest seen with reference to FIGS. 1, 2, and 4 wherein the manifold isshown as mounted in the conventional fashion to obtain pressuremeasurements from a pressurized flowing gas source. In such aconfiguration, the main flow source is generally below the manifold, thepressure sensor/transmitter 12 being secured vertically above and to themanifold 10. It can be seen that should any liquid collect or condensein either of cylindric outlets 48 or 50, and under the assumption thatvalves 23 and 28, respectively, are open, the collected liquid willdrain by gravity through passageways 48 g and 50 g out drain ports 48 hand 50 h, respectively. Likewise, it can be seen that passageways 48 d,50 d, 52 b, and 52 c are all generally sloped in a direction away frominstrument face 36, i.e., toward face 34, further enhancing gravity flowof any fluid that would collect or pool in the relatively shallowcylindric cavities 48 and 50. As noted above, such liquid, if itcontains corrosive materials, can damage the diaphragms and, if itfreezes, cause rupturing of the diaphragms.

With reference to FIG. 5, the manifold is shown as generally invertedfrom the position shown in FIGS. 1, 2, and 4. Generally, but not always,manifold 10 is positioned as shown in FIG. 5 when the fluid beingmeasured is a liquid, in which event the transmitter 12 is mountedvertically below manifold 10, the process fluid from the main flow lineentering manifold 10 from above. Once again, the unique design of thepassageway system of the manifold of the present invention providesunexpected benefits. As noted above, when performing differentialpressure measurements on a liquid medium, it is important that any gasbubbles not be in contact with the diaphragms used in the pressuresensor section of the transmitter lest false readings be obtained. Itcan quickly be seen that any gas bubbles collecting in cylindriccavities 48 and 50 will tend to escape from cavities 48 and 50 and moveupwardly through straight passageways 48 g and 50 g, respectively.Indeed, since, when in the position shown in FIG. 5, all of thepassageways opening into either cylindric cavities 48 and 50 slopeupwardly away from face 36, gas bubble accumulation is virtuallyprecluded in cylindric cavities 48 and 50 because of the naturaltendency of the gas bubbles to rise upwardly through the straight,upwardly sloped passageways.

A desirable feature of the manifold of the present invention is thatthere are no construction holes or bores that are used solely for thepurpose of drilling any of the passageways connecting the variousinlets, outlets, valve cavities, and drain ports. This is a significantadvantage for several reasons. For one, when construction holes areemployed, it is necessary that they be plugged to avoid lead paths outof the manifold. Additionally, such construction holes almost invariablyprovide dead spots where liquid or gas bubbles can be trapped.Furthermore, such construction holes may unnecessarily affect thestructural integrity of the manifold body, which can result in seriousconsequences, depending upon the pressures being handled by themanifold.

As can be best seen with reference to FIGS. 1 and 4, the equalizer valve20 and the block valves 22 and 26 have the axes of their operating stemsgenerally perpendicular to side surfaces 42, 44, and 46, respectively.Stated differently, the valve cavities 52, 48 c, and 50 c can bebisected by an imaginary plane passing through said valve cavities andgenerally parallel to instrument face 36. On the other hand, since ventvalve cavities 48 f and 50 f are generally coaxial with passageways 48 gand 50 g, respectively, valves 24 and 28 are canted relative to valves20, 22, and 26. In particular, as shown in FIG. 1, valves 24 and 28 arecanted downwardly relative to valves 20, 22, and 26. Accordingly, thevent valves 24 and 28 readily stand out from the outer valves,minimizing the likelihood that an operator will actuate the wrongvalve(s).

The manifold of the present invention solves the problem addressed inU.S. Pat. No. 5,277,224 with respect to so-called “smart” pressuretransmitters, i.e., transmitters capable of transmitting both relativeand absolute pressure values. The introduction of the smarttransmitters, exemplified by the 3051C Differential Pressure Transmittermarketed by Rosemount, Inc., Eden Prairie, Minn., resulted in areduction of the distance between the centers of the inlets to thetransmitter from the previous industry standard of 2-⅛″ to 1-¼″.However, while the distance between the centers of the inlets of thedifferential pressure transmitters was reduced, the process fluid inletsfrom the main flow line remained on 2-⅛″ centers. As taught in U.S. Pat.No. 5,277,224, one solution to this problem was to provide what isreferred to a co-planar flange interfaced between the manifold and thetransmitter, the co-planar flange, essentially a flow diverter, servingthe purpose of providing the needed 1-¼″ outlets that would be inregister with the transmitter inlets while maintaining the 2-⅛″ spacingat the outlets of the existing manifolds. The manifold of the presentinvention requires not such co-planar flange or diverter as it is ableto connect, on the process side, with the existing process fluid tapslocated on 2-⅛″ centers and directly couple to the smart transmitter 12having inlets on 1-¼″ centers; i.e., outlets 48 and 50 are in registerwith the inlets to the pressure transmitter 12.

The unique construction of the manifold body of the present inventionminimizes manufacturing costs by minimizing cross-drilling to connectthe various passageways and by utilizing valve cavities and otheroperational ports to form the various passageways necessary to providethe desired fluid communication pathways through the manifold body.

The foregoing description and examples illustrate selected embodimentsof the present invention. In light thereof, variations and modificationswill be suggested to one skilled in the art, all of which are in thespirit and purview of this invention.

What is claimed is:
 1. A valve manifold adapted to be positioned betweena main flow line and a pressure sensor to control fluid flow from saidmain flow line to said pressure sensor, comprising: a manifold bodyhaving a first face, an opposed, substantially planar second face, and aperipheral wall, a high pressure inlet, a low pressure inlet, a highpressure drain port, and a low pressure drain port being formed in saidfirst face, a high pressure outlet and a low pressure outlet beingformed in said second face; an equalizer valve cavity formed in saidperipheral wall, said equalizer valve cavity being in open flowcommunication with said high pressure outlet and said low pressureoutlet; an equalizer valve disposed in said equalizer valve cavity forcontrolling fluid communication between said high pressure outlet andsaid low pressure outlet; a high pressure block valve cavity formed insaid peripheral wall said high pressure block valve cavity, said highpressure inlet, and said high pressure owlet being interconnected, saidhigh pressure block valve cavity and said high pressure outlet beingconnected by a first, straight passageway; high pressure block valvecavity disposed in said high pressure valve cavity for controlling fluidcommunication between said high pressure inlet and said high pressureoutlet; a high pressure vent valve cavity formed in a first,substantially planar side surface of said peripheral wall, said firstside surface being coincident with an imaginary plane forming an acuteangle with said second face; a straight, high pressure vent passagewayconnecting said high pressure vent valve cavity and said high pressureoutlet, said high pressure vent passageway sloping in a direction awayfrom said second face and being normal to said first side surface, saidhigh pressure vent valve cavity and said high pressure drain port beingconnected; a high pressure vent valve disposed in said high pressurevent valve cavity for controlling fluid communication between said highpressure outlet and said high pressure drain port; a low pressure blockvalve cavity formed in said peripheral wall, said low pressure blockvalve cavity, said low pressure inlet, and said low pressure outletbeing interconnected, said low pressure block valve cavity and said lowpressure outlet being connected by a second straight passageway; a lowpressure block valve disposed in low pressure block valve cavity forcontrolling fluid communication between said low pressure inlet and saidlow pressure outlet; a low pressure vent valve cavity formed in asecond, substantially planar side surface of said peripheral wall, saidsecond side surface being coincident with an imaginary plane forming anacute angle with said second face and being opposed to said first sidesurface; a straight, two pressure vent passageway connecting said lowpressure vent valve cavity and said low pressure outlet, said lowpressure vent passageway sloping in a direction away from said secondface and being normal to said second side surface, said low pressurevent valve cavity and said low pressure drain port being connected, anda low pressure vent valve disposed in said low pressure vent valvecavity for controlling fluid communication between said low pressureoutlet and said low pressure drain port said peripheral wall including athird side surface a fourth side surface, and a fifth side surface saidfourth side surface being disposed between said first side surface andsaid first third side surface, said fifth side surface being disposedbetween said second side surface and said third side surface, saidfourth side surface and said fifth side surface forming obtuse angleswith said third side surface, said equalizer valve cavity being disposedin said third side surface, said high pressure block valve cavity beingdisposed in said fourth side surface and said low pressure block valvecavity being disposed in said fifth side surface.
 2. The valve manifoldof claim 1 wherein said high pressure vent valve cavity and said highpressure drain port intersect and said low pressure vent valve cavityand said low pressure drain port intersect.
 3. The valve manifold ofclaim 1 wherein said high pressure block valve cavity is connected tosaid high pressure outlet by a first, straight high pressure passagewayand said low pressure block valve cavity is connected to said lowpressure outlet by a first, straight low pressure passageway.
 4. Thevalve manifold of claim 3 wherein said high pressure and low pressurepassageways slope in a direction away from said second face.
 5. Thevalve manifold of claim 4 wherein said high pressure block valve cavityis connected to said high pressure inlet by a second, straight highpressure passageway and said low pressure block valve cavity isconnected to said low pressure inlet by a second, straight low pressurepassageway.
 6. The valve manifold of claim 1 wherein said high and lowpressure outlets comprise cylindric cavities each having a substantiallyplanar bottom surface and a cylindrical side wall and said high pressureand low pressure vent passageways open into respective ones of saidcylindric cavities through respective ones of said intersections of saidbottom surfaces and said cylindrical side walls.
 7. The valve manifoldof claim 1 wherein said first face of said manifold body issubstantially planar and parallel to said second face of said manifoldbody.
 8. The valve manifold of claim 1 wherein said manifold body isfree of any construction holes used solely for forming any of saidpassageways.
 9. The valve manifold of claim 1 wherein any passagewayopening into either of said high pressure or low pressure outlets slopesaway from said second face.
 10. A method of manufacturing a valvemanifold adapted to be positioned between a main flow line and apressure sensor to control fluid flow from said main flow line to saidpressure sensor without the presence of construction holes which are apotential source of leakage of fluids from said manifold, said methodcomprising: providing a manifold body having a first face, an opposedsubstantially planar second face and a peripheral wall, machining highpressure and low pressure cylindric cavities and high and low pressurecylindric drain ports in said first face; machining a high pressurecylindric cavity and a low pressure cylindric cavity in said secondface, the axes of at least one of ( 1 ) and high pressure cylindriccavity in said second face being axially offset from said high pressurecylindric cavity in said first face or ( 2 ) said low pressure cylindriccavity in said second face being axially offset from said low pressurecylindric cavity in said first face; machining a cylindric high pressureblock valve cavity in said peripheral wall and forming substantiallystraight passageways connecting said cylindric high pressure block valvecavity to each of said high pressure cylindric cavities, machining acylindric low pressure block valve cavity in said peripheral wall andforming substantially straight passageways connecting said cylindric lowpressure block valve cavity to each of said low pressure cylindriccavities; machining a cylindric high pressure vent valve cavity in saidperipheral wall, said cylindric high pressure vent valve cavity in fluidcommunication with said high pressure cylindric drain port; machining acylindric low pressure vent valve cavity in said peripheral wall, saidcylindric low pressure vent valve cavity in fluid communication withsaid low pressure cylindric drain ports; machining a passageway betweensaid high pressure cylindric cavity in said second face and saidcylindric high pressure vent valve cavity in said peripheral wall; andmachining a passageway between said low pressure cylindric cavity insaid second face and said cylindric low pressure vent cavity in saidperipheral wall.
 11. The method of claim 10, wherein each of saidpassageways between each of said high and low pressure cylindriccavities in said second face and their respective cylindric high and lowpressure vent cavities in said peripheral wall slope downwardly.
 12. Themethod of claim 10, further comprising threading each of said highpressure and low pressure cylindric cavities in said first face.
 13. Themethod of claim 10, further comprising machining a cylindric equalizervalve cavity in a peripheral wall.
 14. The method of claim 13, furthercomprising machining a straight passageway from said cylindric equalizervalve cavity to said high pressure cylindric cavity in said second face.15. The method of claim 13, further comprising machining intersectingpassageways, one passageway extending from said cylinder equalizer valvecavity into said manifold body and the other passageway extending fromsaid low pressure cylindric cavity in said second face into saidmanifold body.
 16. The method of claim 10, further comprising machiningfour throughbores through said manifold body, each of said throughboresextending from said first face to said second face and not intersectingany cylindric cavity or passageway in said manifold body.
 17. The methodof claim 10, wherein said peripheral wall slopes inwardly from saidfirst face to said second face in the portion thereof in which thecylindric high pressure and low pressure vent valves are located. 18.The process of claim 10, wherein said high pressure cylindric drain portin said first face intersects said cylindric high pressure vent valvecavity.
 19. The process of claim 10, wherein said low pressure cylindricdrain port in said first face intersects said cylindric low pressurevent valve cavity.
 20. The method of claim 15, wherein each of saidintersecting passageways is sloped such that liquid may flow by gravityfrom said low pressure cylindric cavity towards said cylindric equalizervalve cavity.
 21. A method of manufacturing a valved manifold for usewith a pressure sensing apparatus, said manifold comprising incombination: (a) an integral body having a first face section, a secondface section, generally parallel with the first face section; and aperipheral wall section, the distance between the first and second facesections being smaller than at least one of the width and the length ofthe second face section; (b) a passage system disposed within said bodyand including a plurality of mutually intercommunicating passages; (c)said passage system including: (i) a high pressure inlet; (ii) a highpressure outlet; (iii) a high pressure inlet; (iv) a low pressureoutlet; (v) a vent outlet; (vi) an equalizer valve cavity, saidequalizer valve cavity being connected via a first passageway to saidlow pressure outlet and by a second passageway to said high pressureoutlet; (d) said high and low pressure outlets being disposed in saidfirst face section, said high and low pressure inlets being disposed inat least one of said second face section or in said peripheral wallsection; (e) said first face section being sealingly compatible withrespect to an inlet portion of a housing of a respective pressuresensing apparatus to provide a hermetical sealing engagement therewith,while communicating said high and low pressure outlets with respectiveinlet portions of the pressure sensing apparatus; (f) the spacingbetween the high and low pressure inlets being different from that ofthe spacing between the high and low pressure outlets; said methodcomprising machining each of said intercommunicating passages withoutforming construction holes in said integral body thereby eliminatingpotential leak points.
 22. The method of claim 21, wherein said firstpassageway is a straight passageway.
 23. The method of claim 21, whereinthe manifold is a five valve manifold.
 24. The method of claim 21,wherein only a sole equalizer valve cavity is provided and the methodfurther comprising the step of installing a single equalizer valve insaid sole equalizer valve cavity.
 25. The method of claim 21, whereinsaid second passageway is connected to said high pressure outlet viaintersecting passageways.